Fri March 22, 2013
Project Seeks To Bring Extinct Species Back
JOHN DANKOSKY, HOST:
This is SCIENCE FRIDAY. I'm John Dankosky. It sounds like something from a science fiction movie, researchers using cutting-edge biotech methods to bring an extinct species back to life. As a matter of fact, I think I saw that one. It was called "Jurassic Park."
At a recent symposium in Washington, one team of researchers reported that they'd partial success resurrecting the genome of an extinct species of frog, last seen in Australia in the mid-1980s. Joining me now to talk about the frog effort, called the Lazarus Project, is the head of the team. Michael Archer is professor in the Evolution of Earth and Life Systems Research Group, part of the School of Biological Earth and Environmental Sciences at the University of New South Wales in Sydney, Australia. He joins me by phone, where it's very early Saturday morning there. So welcome, and thanks for joining us on SCIENCE FRIDAY.
MICHAEL ARCHER: Good morning, John. I should say good afternoon to you.
DANKOSKY: Thank you. So how far have you gotten on this project? Do you have a frog yet?
ARCHER: You know, we're much further than we ever thought we would be, and I think probably we're much further than we ever had a right to expect to be. But we don't have the frog yet. What we have is the DNA back and reproducing, and we have it building cells, and it's building even embryos. Now, this is being - it's been a long project, partly because we've been dependent on a host frog, you know, for eggs, and this thing only reproduces over a short period once a year. So we get one little crack at it, and then we have to go cool our heels for a while, and this has been going on. We've only spent about a month and a half. But at this point, this embryo is our next challenge, is to get this embryo to continue to go one to develop a tadpole. So it's one little speed bump after another, but we're knocking them over as we come to them.
DANKOSKY: So why this particular frog?
ARCHER: Yeah, that's a very good question. Well, two good reasons - well, maybe even three. The first one is it represents a whole family of frogs that's gone from the world, and we're all interested in trying to conserve as much of the global genome as we can. That gives the world resilience. That secures even ourselves. So we'd love to have this frog back if we could, because it's so distinctive.
Second reason is, well, it's - medically - a fascinating frog. It's not a normal frog. A normal frog lays its eggs in the water and, you know, they get fertilized, and it wishes them well and then goes off and eats bugs for the rest of its year. This frog didn't do that. This frog was very maternally focused. It swallowed, curiously, the fertilized eggs, and then took them into the stomach.
Now, normally, that's where the food's going to be digested, but somehow this frog shut down all the normal processes that a stomach goes through and turn the stomach, in effect, into a uterus. And there, these fertilized eggs went on to turn into tadpoles in the stomach, and then the tadpoles metamorphosed and became frogs in the stomach. And as they did this, they were getting bigger and bigger, and the poor old female frog is sort of swelling up like a blown-up balloon, eventually can't stand it anymore, has a big hiccup, and out comes a huge spray of little frogs.
ARCHER: And the first biologist who saw this, of course, were just agog. They've never seen any frog - they've never seen any animal, let alone any frog, ever change its bodily organs like this.
So there are all kinds of reasons why we'd love to have this frog back, but that third one that was going to mention is that it's extinct because of us. And I think this goes to this heart of a moral obligation issue. If we're the reason that this big chunk of the global genome and this interesting animal is gone, then I think we've got a moral responsibility, if not a moral imperative to see what we can do to bring it back.
DANKOSKY: Well, and look, we'll get into the morality of all this in just a moment. But as you describe this unusual frog, I guess part of me is wondering, maybe it's just a very inefficient frog. I mean, a frog that lays its babies through its mouth, is it all our fault that this frog went extinct in the first place?
ARCHER: We think it is. One of the things that's been knocking frogs all around the world and has amphibian biologists and everybody else who loves frogs scared to death is something called the chytrid fungus. This fungus is a very nasty bit of work. It is responsible for taking out huge number of species on all the different continents. The problem is it appears it's likely humans are spreading this fungus. We're walking and intruding into pristine environments everywhere around the world and on our clothes, on our boots are probably coming spores of this fungus being shifted around, using us like taxis to find new victims everywhere.
So we're complicit. If this is - and it probably is this because many of the frogs around the world that are disappearing are disappearing from pristine environments. There's no other explanation for why they're going. So we're pretty sure that's what nailed this frog as well. So yeah, we feel a bit guilty about this.
DANKOSKY: So what do you think about re-introducing an extinct species? You can call us: 1-800-989-TALK. That's 1-800-989-8255. I'm sure some of our listeners are probably thinking, is this a really good idea? They did see "Jurassic Park." They wonder, you know, if something's extinct, maybe there's a reason why. Should we really be getting this frog back into the population here?
ARCHER: Yeah, I can understand that view. "Jurassic Park" has had that impact. And, in fact, when you think about that book, Michael Crichton wrote that book specifically to scare people to death about never trying this. I think it was a dismal failure 'cause every kid I know was really excited by that movie and would love to see it happen. But it's not a Velociraptor we're trying to bring back, although remember, of course, dinosaurs are not extinct. We don't have to bring them back. We live with them. There are birds.
Some people have budgie-saurs(ph) as pets, and others go out and gobble up a Kentucky Fried Chicken for lunch. We have dinosaurs all around us. So it's really a different kind of an animal and it's not - we're not reaching that far back. Most of these projects that the Revive and Restore group and National Geographic had been focused on in this event are species that have been recently extinct, and many of these are species that we drove extinct.
My - one of my other interests is trying to get the Australian Thylacine back. That was our continent's king of beasts, and we shot every one of those things to death. So we have a big scorecard here to settle on, I'm afraid.
DANKOSKY: But as you re-introduce species that have been gone for some time, even 30 years, what does it do to the rest of the ecosystem? As we've talked about elsewhere in our program, you know, an awful lot can change evolutionarily in just a few years. So what's the, you know, the downstream consequence here if you put this frog back into the world?
ARCHER: Yeah, that is such an important question, and every one of us involved in projects of this kind around the world have that question right up in our mind. In fact, it often influences your choice about which animal you're going to try to see if you can rescue. And in the case of, for example, the Thylacine, it's an interesting challenge. The Thylacine is an animal we exterminated from Tasmania, that little island south of Australia. I think because that happened, it's possibly going to cause the extinction of one of our other precious animals, the Tasmanian devil.
This is an animal that has a communicable cancer. Dogs have something like that as well. The devil is the only other one. So if devil can meet devil, they can pass this wretched disease on. Now, the Thylacine, when it was in Tasmania, competed with the devil, and you had a balanced system. And if that disease ever popped up in the devil populations, it burned itself out because not all of those devils could come - could contact each other.
If we could get the Thylacine back, put that king of beasts back in the throne, which is still warm and waiting, it would suppress the number of devils, keep them at a manageable level and the disease would burn itself out wherever it started. So getting these ecosystems back by putting in key species can be critical to maintaining the stability of them. You think about Yellowstone National Park. We're all aware of the fact that things started to go terribly wrong when wolves were destroyed from Yellowstone.
The herbivores, the plant eaters began to increase in numbers. They overrate the plants. Their river systems began to degrade 'cause there weren't trees along the edge to protect them. When they get the wolves back, the whole thing starts to fall back into a natural rhythm. So this is driving us, importantly. We do need to know that we could put these animals back and that it would improve the world, not in any way diminish it.
DANKOSKY: Let's go to the phones. Nathan is in San Francisco. Hi, Nathan.
NATHAN: Hi there. Thanks so much for taking my call.
NATHAN: My question is around why we sort of feel a moral obligation to bring species back when species go extinct all the time at the hands of other species. So I guess it's sort why we feel the moral obligation as opposed to seeing it as a sort of natural part of evolution.
ARCHER: I think the answer, Nathan, is pretty simple. You're right, of course. There's nothing immoral or dreadful intrinsically about extinction. In fact, if extinction didn't occur, life wouldn't be able to change in the way that it needs to to adapt to a changing world. It's been going on for three and a half billion years. The problem is, you need new species to originate at about the same rate to offset the ones that are going extinct so that you maintain a balance of the amount of biological diversity in the world.
And that's what's not happening now. You'll hear people talk about the fact that we seem to be now launching into the world's sixth great extinction or mass extinction event where the number of things going extinct is vastly exceeding the number that are appearing. So we're losing - we're net losing species in the world. And as life plunges off this cliff, we have to say, are we the reason that this whole massive global imbalance is starting to happen? And if so, do we want to live with the consequences?
In the previous five mass extinctions on Earth, it took about 10 million years for ecosystems to be balanced again after those dreadful events. Like the meteor when it came at the end of the Cretaceous and took out the dinosaurs. We're kind of doing the same thing now. So the view I have that this is a moral obligation to try to stop this if we can is based on the fact that I want to live in a world that basically has its biological components collapsing. We need those things in the world.
DANKOSKY: So working through your method there, how many different attempts would you need to be successful to really actually rebuild a species? 'Cause if you just have a bunch of frogs that are cloned off of the same frogs, you don't have a whole lot of diversity within the species. It's not like frogs really were back before they were - became extinct in the first place, if you get my meaning.
ARCHER: Yeah, I do. And fortunately, when I went to the chap who had last kept these frogs - this is Professor Mike Tyler at the University of Adelaide - he had not just kept tissues of one frog, he had a whole bucket full of tissues of many frogs, so we know we've got, you know, male, female tissue. But technology is getting so good now. Many of these questions that we have presumed to be important - i.e., we have to have hundreds of different kinds of, or different individuals to have a viable population, it's not clearly the case that that's necessary anymore.
Sometimes genetic variation could be engineered. Sometimes it will pop up itself even in a population that is very little. The cheetah, for example, really every cheetah is a clone of every other cheetah and yet they're doing fine. There's not much genetic variation there at all.
And we do know that you can, in fact, do letter by letter gene replacement therapies now - these are all new - where you can introduce variation into populations that wasn't there. You can swap one little piece of DNA for another. This is a new world and it's so exciting because it offers the potential to increase the viability of the natural world in a way that we've never been able to do before.
DANKOSKY: I'm John Dankosky, and this is SCIENCE FRIDAY from NPR.
So what about some of the species that are icons of modern extinctions, things like the passenger pigeon? Could you bring that back?
ARCHER: Yeah. It's very interesting to see that, revive and restore. And Ben Novak are working very hard on that. George Church is working as well. One of the good things, you know, that happened in this meeting were all of us came out of our closets and admitted what we were trying to do, was that we met each other. And as a result of this meeting organized by these organizations, a lot of new collaborations developed. So I already know that there are three or four different groups combining their efforts together to try to get that passenger pigeon back. The same thing is happening with the mammoth.
In the case of our gastric-brooding frog, we've teamed up with Advanced Cell Technology, Bob Lancer. who's a brilliant cloner of mammals. So I think we're going to suddenly see an acceleration in these projects. Many interesting animals that have been the target of de-extinction events are going to accelerate their path back into the world. That's what I hope, anyway.
DANKOSKY: Shannon is on the phone in Haymarket, Virginia. Hi there, Shannon.
SHANNON: Hello. How are you?
DANKOSKY: Doing well. What's on your mind?
SHANNON: I'm curious - you brought up the morality issue, and I'm curious if you're getting any kind of pushback from either the scientific community or anywhere else, and to see whether or not this is wise and what will happen if people who don't necessarily have the appropriate tools to do the right kind of research - or maybe even just the appropriate intentions in mind get a hold of this kind of technology. And is anyone worried that you're going to take it too far?
ARCHER: Yeah. Shannon, that's very interesting and a very good question, and it is something we're all thinking about. But the first answer to your question, are we getting pushback? Not a lot. We're getting exactly the kind of question you've asked, which is informed concern about - everybody wants to know that these issues are being talk about.
But in this particular case, one of the most curious objections or concerns I heard expressed comes from conservationists themselves. They're little worried that we actually may succeed. And they're worried because if we do, they're going to say, well, why are people going to bother to do standard conservation projects anymore? If you can haul an animal back up the cliff after it's fallen off and gone extinct, why waste all this energy trying to conserve them now?
And there are lot of reasons why this is - while a good worry, not one that we really do have to worry about. In the first place, we haven't done it yet, so, you know, we all have our fingers crossed and we're working hard.
Second place, it's actually cheaper and easier to look after endangered species today than to try to pull them back up the cliff again afterwards. The third reason, which I think is most important, is the technology that we're developing to try to bring an extinct animal back always involves trying to take your DNA from the extinct animal and put it into the cell of a completely different species because the species you want isn't here any more.
So this is very different than Dolly cloning, when they took the nucleus from a live sheep body cell and put it into the egg of a live sheep. This is a much more challenging issue. But if we succeed, then those endangered animals that we're all concerned about seeing disappear off that cliff and their numbers are reducing, we can use that technology if we can refine it to take the endangered species DNA, put it into the egg of a common species - a different one - and use the common species to increase the numbers of the endangered species.
DANKOSKY: Actually build up a population that's in decline.
ARCHER: Exactly. So I see this as another tool that conservationist actually need and will probably embrace to assist all of the projects, all of the efforts globally to keep as many species in the world as we can.
DANKOSKY: Well, thank you very much for getting up early to talk about this bizarre and interesting experiment. Thank you so much, Michael Archer.
ARCHER: It was a pleasure, John, and thank you to your listeners for asking those very intelligent questions.
DANKOSKY: Michael Archer is a professor in the Evolution of Earth and Life Systems Research Group, part of the School of Biological, Earth and Environmental Sciences at the University of New South Wales in Sydney, Australia. Transcript provided by NPR, Copyright NPR.